Fluid-mixing device



April 28, 11 -925.

J. W. F. MACDONALD FLUID'MI'XING DEVICE Fild sept. 25; 1922 Fig.1.

John WEM lnven'Tor.

donqld April 28; 1925. f

1 1,535,428 J. W. F. MACDONALD FLUID MIXING DEVICE Filed Sept. 23. 1922 4 Sheets-Sheet 2 Y Fig.3.

In venTo'r.

,John W. F. Mucdonuld byWMA'W I Aflya" Patented Apr. 28, 1925.

UNITED STATES JOHN W. F. MACDONALD, OF BRIGHTON, MASSACHUSETTS.

FLUID-MIXING DEVICE.

Application filed September 23, 1822. Serial No. 590,051.

To all whom it may 0071mm:

Be it known that I, JOHN XV. F. MAG DONALD, a citizen of the United States, and resident of Brighton, county of Suffolk, State of Massachusetts, have invented an Improvement in l luid-h/Iixing Devices, of which the following description, in connec tion with the accompanying drawing, isa specification, like characters on the drawing representing like parts.

This invention relates to improvements in fluid mixing devices and the principal object thereof is to provide a fluid mixing device comprising conduits for the respective fluids with means operable to maintain a predetermined correlation between the amounts of fluid delivered by the respective conduits irrespective of the aggregate amount of fluids delivered.

A further object of the invention is to provide means for adjusting the relative proportions of the fluids delivered by said conduits and further for maintaining the same relative proportions of fluids delivered which are established by such adjustment.

More specifically the invention relates to means for adjusting the valves which control the delivery of fluids through independent conduits in such a manner that the valves may be simultaneously actuated so as to provide for the delivery of a predetermined amount of fluid from each conduit. This preferably is accomplished by providing valve actuating levers for the respective alves which are simultaneously operated, but provided respectively with adjustable fulcrums by which the relative leverages of the valve actuating levers may be adjusted.

The invention is disclosed herein as applied to a fluid mixing device for a liquid fuel burner and a further object of the invention is to provide means for limiting the movements of the valves so as to prevent the extinguishment of the flame in the burner. 1

A further feature of the invention consists in providing means for preventing the delivery of an excess amount of the fluids to the burner in order that overheating from the burner n'iay be prevented.

A further object of the invention is to provide a liquid fuel burner of the character described with automatic means for controlling the amounts of fluids delivered to the burner by thermostatic means which preferably is subject to the influence of the temperature of the medium which is heated by the burner.

Other objects and features of the invention will more fully appear from the following description and the accompanying drawings and will be pointed out in the claims.

.In the drawings:

Fig. 1 is an elevation showing the device for regulating the flow of fluids through two conduits leading to the burner of a heater and also illustrating the thermostatic means for controlling the action of the regulating means; i

Fig. 2 is a detail view, partially in section, showing the thermo-expansible element located in the elbow of a conduit through which the heat transporting means is de livered from the heater;

Fig. 3 is a front elevation of the regulating device;

Fig. i is a side elevation of the same;

Fig. 5 is a detail elevation, partly in section, showing particularly the manner in which the valve actuating levers are connectedto the actuator; and,

Fig. 6 is a longitudinal vertical sectional view through the regulating device and conduits, the actuator, the valve actuating levers, valve stems and valves being shown in elevation.

The fluid mixing device is disclosed in the drawings as applied to an oil burning furnace for heating a heat transporting fluid which'is conducted by suitable conduits to a radiator or other heat-utilizing device.

In the usual operation of oil burners for furnaces of this type and other heaters which are regulated by hand it is necessary to adjust the oil supply and the air or steam used for atomizing simultaneously. Every change in the rate of flow of the oil or the amount burned in certain periods must be accompanied by a corresponding adjustment in the amount of air under pressure or steam used in order to provide proper conditions for good combustion. For example, if an oil burner having a minimum to maximum capacity range of from three to fifteen gallons per hour is adjusted so that it is operating properly at nine gallons per hour and the oil supply is reduced without adjusting the air or steam, the burner would be'receiving an excessive air or steam supply and would probably blow out before reaching its minimum capacity. On the other hand, if the oil supply was opened up so as to increase the capacity of the burner without adjusting the. air valve there would be an insuflicient supply of air or steam and consequently incomplete combustion.

It is very desirable at times to regulate automatically the capacity of the oil burner so as to maintain a uniform temperature in the material to be heated. Some attempts have been made to control oil burners and other liuid burners thermostatically where the fuel supply lines and air supply lines are titted with inde 'iendent shut-off valves each operated either electri ally or by a diaphragm motor. lhese valves are arranged so that when the temperature of the medium which is being heated rises beyond a set point the alve will shut off entirely, but a by-pass is provided around each valve. set with a minimum opening. so that sulticient fuel and air is supplied to keep the burner lighted. t nder such conditions the burner operates properly at two points, that is. either at its maximum or minimum setting. In the majority of. thermostatic temperature regulating devices a thermo-cxpansive element is subjected to the ten'iperature of the material which is being heated and the expansion or contraction of said thermostatic device. acts to open or close a small relay valve which regulates a supply of air under pressure to or from a diaphragm motor which in turn opens or closes a shut-off valve in the oil supply line. It will readily be seen that the capacity range of such a device. is very limited as the air conditions remain constant for a variable condition of oil supply. In the present invention means are provided for. simultaneously. properly correlating the amounts of the fuel and vaporizing an atomizing fluid supplied l;ll]()l1 ll0llt the capacity ran"e of the burner.

The furnace to which the burner is adapted may be of the type disclosed in my prior Patent Xo. 1.301.863. granted April 29, 1915), or to any other suitable furnace.

The apparatus disclosed in Fig. 1 comprises a furnace 1 having a suitable fire-box and provided with suitable means for heating a liquid which is transported to a radiator or other heat utilizing device. The conduit for the heating fluid comprises an inlet conduit 2 which may communicate with suitable headers within the heating chamber of the furnace and a delivery conduit 3 formmg a continuation of the conduit within the chamber and communicating therewith through an elbow at as disclosed in my prior patent. aforesaid.

The furnace desirably is heated by a liquid fuel burner 5 which extends through a suitable opening 6 in the. wall of the fire-box and is supplied with a combustible liquid.

such as, hydro-carbon, through a conduit 7 and with a vaporizing and oxidizing fluid, such as, air or steam under pressure, which is delivered to the burner through a conduit 8. The conduits 7 and 8 are provided respectively with valve casings 9 and 10 which are controlled by a regulating mechanism embodying the present invention and which is designed so to correlate the amount of fuel and the vaporizing and oxygen-supplying medium as to produce a substantially perfect comluistion, and also to maintain these proper proportions while regulating the aggregate amount supplied in correlation to the demands imposed upon the heater.

The regulating device illustrated herein comprises a frame having a base 11 which desirably is seated on the valve casings 9 and 1t) and is provided with four, preferably upwardly extending. standards 12 having laterally extending branches 13 and 14. and a su perstructure 15 upon which is seated the dome-shaped member 16 of a pneumatic motor the flexible diaphragm 17 of which is clamped between the flange 18 of said domeshaped member and a flange 19 of the superstructure.

The valve casings 9 and 10 are provided with cylindrical portions which are divided by horizontal partitions 2t) and 21 providing upper and lower chambers, the fluid being supplied through the lower chamber and delivered through the upper chamber. These partitions are provided with cylindrical alve seats 22 and 23 upon which valves 24- and 25 are seated. The valves 24 and 25 preferably are provided with tubular extensions which have upwardly converging slots 26 adapted tov progressively increase the port area as the valves are raised.

The upper portions of the valve casings 5) and 1t) consist in unions 2? and 28 which are joinedto the cylindrical portions of the valve casings by screw threaded connections. 'lhcse unions desirably are turned down to present cylindrical extensions 29 and 30 presenting shoulders 31 and 32 which form seats for the. base 11 of the frame. Nuts 33 and 3s upon the screw threaded portions of the cylindrical extensions 29 and 30 serve to clamp the base 31 of the frame firmly upor the unions 27 and 28.

The unions 2? and 28 are provided with vertically extending apertures to receive the stems 35 and 36 of the valves 24 and 25 and suitable stuffing boxes 37 and 38 are screwed upon the upper ends of the cylimlrical extensions 29 and 3.0.

The valve stems 35 and 36 are connected respectively at their upper ends to yokes 39 and 40 and springs 41 and 42 are interposed l'ietween the upper ends of the stufling boxes 37 and 38 and nuts 43 and 44 located upon downward extensions of the yoke members.

The yoke members 39 and 40 are respectively connected by links 4-5 and 46 to arms 47 and d8 of levers l9 and 50. The ends of the other arms 51 and 52 of said levers extend into an aperture in an enlarged portion of an actuator 53 and are pivotally connected thereto by a pin 54 which extends through the walls of said aperture and also through the ends of the arms 51 and 52.

The actuator 53 desirably is in the general form of a cylindrical rod having turneddown end portions and 56 which respectively are slidably mounted in adjustable bearing members 57 and 58. the upper bearing member 57 being carried by a transverse web 59 of the frame and the lower bearing member 58 by a cylindrical boss 60 located .rentrally of the base portion of the frame.

The lower portion of the actuator 53 is provided with a shoulder 61 which is adapted to engage the enlarged head of the hearing member and thereby to limit the downward movement of the actuator. The upper portion of the actuator likewiseis provided with an enlarged portion presenting a shoulder 62 which is adapted to engage the head of the bearing member 57. Therefore, by adjusting the bearing members 57 and 58 respectively the range of reciprocation of the actuator may be limited and the maximum and minimum amounts of fluid delivered through the conduits thereby determined.

The levers 49 and 50 are fulcrumed upon the casing upon pivots which desirably are adjustable so that the relative lengths of the levers L9 and 50 may be varied in such a manner as to independently control the movements of the valves which are opened or closed by the movement of the actuator.

In the preferred construction illustrated herein the fulcrums for the respective levers are in the form of pins or shafts 63 and 64 having flattened portions which are slidably mounted in slots in the levers 49 and 50 re-.

spectively. The pins (33 and 6st are rotatably mounted in depending arms of cross heads 65 and 66 which are slidably mounted upon parallel bars 67 which pass through and are anchored to the lateral extensions 13 and let of the frame. The cross heads 65 and 66 are provided with upwardly extending members having bosses 67 and 68 which receive adjusting screws 69 and 70. The adjusting screws are provided with cylindrical extensions which desirably are rotatably journalled in bushings 71 and 72 in the lateral extensions 18 and 14 of the frame and have milled heads 73 and 74 by which they may be conveniently rotated. The bushings preferably are secured in place by suitable set screws 71 and 72.

In order to prevent end-wise movement of the adjusting screws the heads 78 and 7d are provided with hubs which abut against the outer ends of the bushings 71, 72 and with collars 75 and 76 which abut against the inner ends of said bushings. For convenience in construction and assembly the col.- lars 75 and 76 desirably are of the same or a smaller diameter than the external diam eter of the bushings so that the screws, their collars and bushings may be assembled and thereafter introduced through the apertures in the frame and the bushings then secured in the frame by the set screws 71 and 72".

By reason of this construction the screws 69 and may be actuated to slide the cross heads laterally and thereby to adjust the fulcrums of the levers 49 and 50 respectively so that the relative leverages, through which the actuator moves the valves 24 and 25, may be varied to maintain the same proportions of the respective fluids delivered by the conduit throughout the range of movement of the actuator.

Resilient means are provided which normally tend to force the actuator in a direction to close the valves. In the preferred construction a spring 77 is connected at its upper end to a boss 78 upon the superstructure of the frame and at its lower end is connected to an eye in a link 79 which passes through a stud S0 in a lever 81 and is provided with a screw threaded end portion having nuts by means of which the posi tion of the link 79 may be varied to vary the tension upon the spring a collar being interposed between the nuts and the pivotal stud 80. The lever 81 passes through an opening in an enlarged portion 84 in the actuator and is pivotally connected to the actuator by a pin 85. The other end of the lever is fulcrumed upon a pin 86 carried by bosses 87 upon the frame.

In the preferred construction of the device illustrated the ends of the levers 49 and 50 extend into the aperture in an enlarged portion 88 of the actuator which is similar in construction to the enlarged portion 84-. but located at right angles thereto, the ends of the lever being pivotally mounted in such enlarged portion by the pin heretofore described.

In order to provide for automatically controlling the moven'ients of the actuator the upper end of the actuator is provided with a spherically curved head 89 which engages the flexible diaphragu'i 17, of the pneumatic motor.

The dome-shaped member 16 is provided with a central boss 90 having an aperture therethrough provided with a screw threaded boss to receive the end of a pipe 91 through which a fluid under pressure, such. as. air under pressure, may be introduced to actuate the diaphragm 17 and through it to move the actuator.

Suitable thermostatic means is provided for controlling the flow of fluid under pressure into the pneumatic motor. such thermostatic means desirably being subject to the influence of the temperature of the medium which is heated by the burner.

In the particular embodin'ient of the invention disclosed herein, a thermostatic member, such as a tube or capsule 92, containing an expansible or a volatile fluid, is located in the elbow of the delivery conduit 3 through which the heat transporting liquid is delivered from the furnace. A. tube 9;) e:' tends from this capsule to a thermostatic valve mechanism 9% which may be of the usual commercial type which is employed in regulating the supply of compressed air or other lluid from a supply pipe 95 to the pipe 91 leading to the pneun'iatic motor. Pressure gauges 96 and 97 may be connected to the pipes 95 and 91 to indicate the respective pressures in these pipes. A filter 98 may be introduced in the compressed air line 95 to prevent dust 01' other foreign matter from being carried into the thermostatic regu later 94.

in the operation of the device, therefore, the temperature of the medium which is heated by the burner serves thermostatically to control the amount of fluid under pressure which is delivered to the diaphragm motor of the regulator. 'When the temperature of the heat transporting fluid is below a predete mined ten'iperature the fluid under pressure is permitted to flow through the thermostatic valve mechanism 9% into the chamber between the diaphragm 17 and the dome 16 of the regulator.

The building up of the pressure in this chamber forces the head of the actuator 89 downwardly, thus rocking the levers 525) and 50 upon their fulcrums 23 and (ll and raising the 'alves sulliciently to peri'uit an increased amount of liuid to flow through the conduits l) and 10 to the burner.

\Vhen the heat transporting liquid has been heated to a predetermined ten'iperature the expansion of the volatile fluid in the capsule 92 opens a bleeder in the thermostatic valve and permits the air under pressure to cape slowly from the chamber in the diaphragm motor. The spring 77 thereupon raises the actuator. thus rocking the levers it) and 50 in the opposite direction around their respective pivots (53 and ($4, gradually clos iug the valves.

By reason of this construction the amount of fuel and vaj'iorizing and oxygen-supply ing mediums to the burner will be increased and diminished in correlation to the demands of the burner to maintain the heat transporting liquid at a predetern'iined temperature and this proportion will be maintained throughout the range of movement of the actuator irrespective of the aggregate amount of the fluids delivered to the burner.

lly adjusting the respective fulcrums oz; and (i-l: oil the levers l9 and 50 the relative proportions of fuel and vaporizing and oxygen-supplying fluid may be regulated with exceeding accuracy so that the same proportions of the liquids will be maintained throughout the range of movement of the actuator as established by such adj ustinent.

The ratio, therefore, of these fluids may be so adjusted that proper conditions for substantially perfect combustion may be main tained at any *apacity within the range of the burner.

By adjusting the bearing members 5T anfl 58, which form stops to limit the range of movement of the actuator, the maximum and minimum limits of movement of the valves, may be adjusted so that the valves may be prevented from entirely closing. Thus by adjusting the bearing or stop 57 the valves can be prevented from entirely closing so that the burner will. not be extinguished and the necessity of a pilot light avoided. adjusting the hearing or stop the maximum supply to the burner may be limited.

In the original adjustment of the valves the two fulcrum pins (ill and til and the central pin 54. which connects the actuator to the ends of the levers 4:9 and 50, are arranged in alinement with the valves closed. The upper bearing or stop 5? is then screwed down to engage the shoulder e2 upon the actuator so that the oil valve will stay open just enough to supply sulticient an'iount of fuel to maintain the burner at its minimum capacity. The fulcrum 6-l of the air valve is then adjusted to give the proper proportion of vaporizing and oxygen-supplying fluid to the burner. The air line leading to the pneumatic chamber of the regulator is then opened so that fluid under 1 essure is introduced into the diaphragm motor. This causes both valves to be raised and the amount of fluid supplied to the burner increased. if it is found that there not a sullicient amount of vaporizing and oxygensupplying fluid furnished for the larger capacities of adjustment the fulcrum (it of the air valve is moved inward, thus giving the valve stem 36 a longer range of movement and consequently increasing the supply of vaporizing fluid. If an increased amount of fuel is required the fulcrum 63 may likewise be adjusted so that by properly setting the fulcrums G3 and 64 of the levers which control the respective valves a proper relation between the fuel and the vaporizing and oxygen-supplying agent may be established to maintain a si'ibstantially perfect combus tion and when once established these proportions will be maintained throughout the. range of moven'ient of the actuator under its thermostatic control.

\l'hile the invention has been particularly described herein in respect to its application to a fuel burner it will be obvious that it may be employed for the purpose of mixing any two fluids under pressure, either with or without the tllQl'll'lOSttitiC control as may he required for the conditions under which the device is operated.

It will be understood that the embodiment of the invention disclosed herein illustrative and is not restrictive and that various changes in form, construction and arrangement of parts may be made within the spirit and scope of the following claims.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is:

1. A fluid mixing device comprising conduits for the respective fluids to be mixed, a frame connected to said conduits, valves in said conduits, *alve actuating levers, brackets slidably mounted on said frame having fulcrums for the respective valve actuating levers, screws mounted in said brackets and frame operable to adjust the positions of the respective, fulcrums and thereby vary the effective lengths of the respective levers, means connecting each valve actuating lever to its valve and a. reciprocable actuator connected to said valve ac tuating levers operable sii'l'niltaneously to actuate said levers and their valves.

A fluid mixing device for a liquid fuel burner having independent conduits for sup iilying respectively liquid fuel and an oxidizing agent, a frame connected to said conduits, valves in said conduits having stems slidably mounted in said frame, levers connected at their outer ends to the respective valves, fulcrunis for said levers inde- PCDdQDtly inovably mounted on said frame, means including screws for adjusting said "ulcrulus to vary the effective lengths of the respective levers, an actuator reciprocably mounted on said frame connected to the inner ends of said levers and automatic thern'iostatically controlled means for moving said actuator.

3. A fluid mixing device for a liquid fuel burner having independent conduits for supplying respectively liquid fuel and an oxidizing agent, a frame connected to said conduits, valves in said conduits having stems slidably mounted in said frame, levers connected at their outer ends to the respective valves, fulcrums for said levers indedently and adjustably mounted on said frame, an actuator reciprocably mounted on said frame connected to the inner ends of said levers. resilient means tending normally to close said valves and automatic thermostatically controlled means engaging 60 said actuator acting normally to open said valves.

4. A fluid mixing device for a liquid fuel burner having independent conduits for su 'iplying respectively liquid fuel and an oxidizing agent, a frame connected to said conduits, valves in said conduits having stems slidably mounted in said frame, levers connected at their outer ends to the respective valves, fulcrums for said levers inde pendently and adjustably mounted on said frame, an actuator reciprocably mounted on said frame connected to the inner ends of said levers, resilient means tending normally to close said valves, automatic thermostati cally controlled means engaging said ac tuator acting normally to open said valves and adjustable .n'ieans for limiting the movement of said actuator to prevent closing of the valves and the extinguishment of the flame in the burner.

A fluid mixing device for a liquid fuel burner having independent conduits for supplying respectively liquid fuel and an oxidizing agent, a frame connected to said conduits, valves in said conduits having stems slidably mounted in said frame, levers connected at their outer ends to the respective valves, fulcruins for said levers independently movably mounted on said frame, means including screws for adjusting said fulcrums, an actuator reciprocably mounted on said frame connected to the inner ends of said levers, resilient means teiulling normally to close said valves, automatic thermostatically controlled means engaging said actuator acting normally to open said valves, adjustable means adapted to engage said actuator to limit the extent to which said valves are opened and adjustable means for limiting the movement of said actuator to prevent closing of said valves and the extinguislnnent of the flame in the burner.

(3. A fluid mixing device for a liquid fuel burner having indepcmlent conduits for supplying respectively liquid fuel and an oxidizing agent, a frame connected to said conduits, valves in said conduits having stems slidably mounted in said frame, levers connected at their outer ends to the respective valves, fulcruins for said levers independently and adjustably mounted on said. frame, an actuator reciprocably mounted on said frame connected to the inner ends of said levers, resilient means engaging said actuator tending normally to close said valves, a pneun'iatically operated motor mounted on said frame connected to said actuator operable to open the valves and thermostatic means subject to the influence of the medium which is heated by the burner for controlling the operation of said motor.

In testimony whereof, I have signed my name to this specification.

JOHN lV. F. MACDONALD. 

